Fair Value Of Financial Instruments

12 Months Ended

Mar. 31, 2012

Fair Value Of Financial Instruments [Abstract]

Fair Value Of Financial Instruments

4.Fair Value of Financial Instruments

The Company has determined that the only assets and liabilities in the Company’s financial statements that are required to be measured at fair value on a recurring basis are the Company’s investment portfolio assets. The Company defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.The Company applies the following fair value hierarchy, which prioritizes the inputs used to measure fair value into three levels and bases the categorization within the hierarchy upon the lowest level of input that is available and significant to the fair value measurement. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements).

• Level 1 — Quoted prices in active markets for identical assets or liabilities.

• Level 2 — Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

• Level 3 — Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

The Company’s investment portfolio assets consist of corporate debt securities, money market funds, U.S. Treasury securities, obligations of U.S. government-sponsored enterprises, and commercial paper, and are reflected on our consolidated balance sheet under the headings cash and cash equivalents, restricted investments, marketable securities, and long-term marketable securities.The Company determines the fair value of its investment portfolio assets by obtaining non-binding market prices from its third-party portfolio managers on the last day of the quarter, whose sources may use quoted prices in active markets for identical assets (Level 1 inputs) or inputs other than quoted prices that are observable either directly or indirectly (Level 2 inputs) in determining fair value.

As of March 26, 2011, the Company classified all investment portfolio assets as Level 1 inputs.In fiscal year 2012,the Company determined that certain of its available-for-sale marketable securities should have been classified as Level2.These changes in the disclosed classification had no effect on the reported fair values of these investments.Prior period amounts have been reclassified to properly present the securities as Level 2.  The Company has no Level 3 assets.

The fair value of our financial assets at March 31, 2012, was determined using the following inputs (in thousands):

	Quoted Prices
	in Active		Significant
	Markets for		Other		Significant
	Identical		Observable		Unobservable
	Assets		Inputs		Inputs
Description	Level 1		Level 2		Level 3		Total
Cash equivalents
Money market funds...........................................	$	40,557	$	—	$	—	$	40,557
Commercial paper...............................................		—		15,952		—		15,952
Corporate debt securities....................................		—		1,112		—		1,112
	$	40,557	$	17,064	$	—	$	57,621
Available-for-sale securities
Corporate debt securities....................................	$	—	$	48,025	$	—	$	48,025
U.S. Treasury securities.....................................		30,261		—		—		30,261
Agency discount notes........................................		—		16,796		—		16,796
Commercial paper...............................................		—		23,709		—		23,709
	$	30,261	$	88,530	$	—	$	118,791

The fair value of our financial assets at March 26, 2011, was determined using the following inputs (in thousands):

	Quoted Prices
	in Active		Significant
	Markets for		Other		Significant
	Identical		Observable		Unobservable
	Assets		Inputs		Inputs
Description	Level 1		Level 2		Level 3		Total
Cash equivalents
Money market funds................................................	$	17,700	$	—	$	—	$	17,700
Commercial paper...................................................		—		4,999		—		4,999
U.S. Treasury securities...........................................		—		10,500		—		10,500
	$	17,700	$	15,499	$	—	$	33,199
Available-for-sale securities
Corporate debt securities.........................................	$	—	$	64,212	$	—	$	64,212
U.S. Treasury securities...........................................		35,281		—		—		35,281
Agency discount notes.............................................		—		16,591		—		16,591
Commercial paper...................................................		—		56,146		—		56,146
	$	35,281	$	136,949	$	—	$	172,230